Oxidation, ignition and combustion of toluene: Experimental and detailed chemical kinetic modeling

Article abstract of DOI:10.1039/b110282f

The oxidation of toluene was studied in a jet-stirred reactor at 1 atm. New experimental results were obtained over the high temperature range 1000-1375 K, and variable equivalence ratio (0.5 ≤ φ ≤ 1.5). Concentration profiles of reactants, stable intermediates and final products were measured by probe sampling followed by online and off-line GC analyses. These experiments were modeled using a detailed kinetic reaction mechanism (120 species and 920 reactions, most of them reversible). This kinetic scheme was also used to simulate the ignition of toluene-oxygen-argon mixtures and the burning velocities of toluene-air mixtures. The presently proposed mechanism has already been validated by simulating the oxidation of benzene at 0.46 to 10 atm under stirred-reactor conditions, the ignition of benzene-oxygen-argon mixtures and the combustion of benzene in flames. Sensitivity analyses and reaction path analyses, based on species rates of reaction, were used to interpret the results. The routes involved in toluene oxidation have been delineated: toluene oxidation proceeds via the formation of benzyl, by H-atom abstraction, and the formation of benzene, by H-atom displacement yielding methyl and benzene; benzyl oxidation yields benzaldehyde, that further reacts yielding phenyl whereas benzyl thermal decomposition yields acetylene and cyclopentadienyl; further reactions of cyclopentadienyl yield vinylacetylene.

Full text of DOI:10.1039/b110282f

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Oxidation, ignition and combustion of toluene: Experimental and
detailed chemical kinetic modelingy
P. Dagaut,* G. Pengloan and A. Ristori
C.N.R.S., Laboratoire de Combustion et Syst e` mes R e´ actifs, 1C, Avenue de la Recherche
Scientifique, 45071 Orl e´ ans Cedex 2, France. E-mail: dagaut@cnrs-orleans.fr
Received 9th November 2001, Accepted 25th February 2002
First published as an Advance Article on the web 18th April 2002
The oxidation of toluene was studied in a jet-stirred reactor at 1 atm. New experimental results were obtained
over the high temperature range 1000–1375 K, and variable equivalence ratio (0.5 p j p 1.5). Concentration
profiles of reactants, stable intermediates and final products were measured by probe sampling followed by on-
line and off-line GC analyses. These experiments were modeled using a detailed kinetic reaction mechanism (120
species and 920 reactions, most of them reversible). This kinetic scheme was also used to simulate the ignition of
toluene–oxygen–argon mixtures and the burning velocities of toluene–air mixtures. The presently proposed
mechanism has already been validated by simulating the oxidation of benzene at 0.46 to 10 atm under stirred-
reactor conditions, the ignition of benzene–oxygen–argon mixtures and the combustion of benzene in flames.
Sensitivity analyses and reaction path analyses, based on species rates of reaction, were used to interpret the
results. The routes involved in toluene oxidation have been delineated: toluene oxidation proceeds via the
formation of benzyl, by H-atom abstraction, and the formation of benzene, by H-atom displacement yielding
methyl and benzene; benzyl oxidation yields benzaldehyde, that further reacts yielding phenyl whereas benzyl
thermal decomposition yields acetylene and cyclopentadienyl; further reactions of cyclopentadienyl yield
vinylacetylene.
fully used to simulate benzene oxidation, ignition and combus-
tion, against these new experimental results.
Introduction
Toluene is present in commercial gasoline, it is also easily
formed from the oxidation of hydrocarbons and commercial
fuels used in S.I. engines, Diesel engines and aircraft. The emis-
sions of toluene via gasoline evaporation and from combustion
are of major concern due not only to its own toxicity but also
to the formation of other toxic compounds by oxidation in the
Experimental set-up
The JSR experimental set-up used in this work is similar to
It consists of a 40 mm diameter
1
13,14
troposphere. Only a limited number of kinetic studies dealing
with the combustion of toluene have been reported in the lit-
that described earlier.
3
sphere (30.5 cm ) made of fused silica (to prevent wall catalytic
reactions). It has four nozzles of 1 mm id for the admission
of the gases which achieve the stirring. A nitrogen flow of
2
,3
erature. Burcat et al. measured the ignition delays of simple
aromatics including toluene–oxygen–argon mixtures behind a
reflected shock wave. The oxidation of toluene was studied
in a turbulent plug flow reactor (PFR) at 1 atm and ꢀ1200
ꢁ
1
100 L h is used to dilute the fuel. All the gases are preheated
before injection, minimizing temperature gradients inside the
JSR. A regulated heating wire of ꢀ1.5 kW maintains the tem-
perature of the reactor at the desired working temperature.
4
K.
–7
The kinetics of toluene oxidation was also studied in a
static reactor by addition of toluene to a reacting H
8
ture at 773 K. Davis et al.
2
+ O
measured the laminar flame
2
mix-
9,10
The reactants are diluted by nitrogen (<50 ppm of O and
2
speeds of toluene–air mixtures at 1 atm and proposed a kinetic
scheme derived from a previous modeling effort to simulate
H O; <1000 ppm of Ar; <5 ppm of H ), and mixed at the
2
2
7
13
entrance of the injectors. High purity reactants were used:
oxygen 99.995% and toluene >99.5%. Toluene was thor-
oughly sonically degassed before use. A piston pump (Isco
100 DM) was used to deliver toluene to an atomizer–vaporizer
toluene–air flame speeds and major species measured in a tur-
bulent PFR. The oxidation of toluene and n-butane–toluene
1
1
mixtures was studied in a turbulent PFR and a kinetic
mechanism derived from ref. 7 was proposed. A more compre-
hensive kinetic modeling of toluene pyrolysis and combustion
ꢂ
assembly maintained at 150 C. Good thermal homogeneity
along the whole vertical axis of the reactor was observed for
each experiment by thermocouple (0.1 mm Pt–Pt/Rh 10%
located inside a thin-wall silica tube) measurements (typical
change p5 K). The reacting mixtures were probe-sampled
by means of a low-pressure sonic quartz probe. The samples
(p30 Torr ꢃ 4 kPa) were taken at steady temperature and resi-
dence time and analyzed on-line by means of a GC-MS (Var-
ian Saturn) and off-line, after collection in 1 L Pyrex bulbs.
Low vapor-pressure species were analyzed on-line whereas
high vapor-pressure compounds and permanent gases were
analyzed off-line. The experiments were performed at steady
1
2
was presented by Lindstedt and Maurice.
The present paper has two main objectives: (i) to obtain new
experimental kinetic results for the oxidation of toluene at 1
atm in a jet-stirred reactor (JSR) over a wide range of equiva-
lence ratio and temperature and (ii) to further validate a
detailed chemical kinetic reaction mechanism, already success-
y Electronic supplementary information (ESI) available: Arrhenius
parameters for reactions. See http://www.rsc.org/suppdata/cp/b1/
b110282f/
1
846
Phys. Chem. Chem. Phys., 2002, 4, 1846–1854
This journal is # The Owner Societies 2002
DOI: 10.1039/b110282f

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state, at a constant mean residence time, the reactants flowing
continually in the reactor, varying stepwise the temperature of
the gases inside the JSR. A high degree of dilution was used
of that used in the prediction of benzene formation in pre-
vious work dealing with the oxidation of unsaturated hydro-
2
0,26
7
It follows a general oxidation scheme that also
The
carbons.
served as a basis in previous modeling efforts.
9
,11,12
(
0.15% vol. of fuel), reducing temperature gradients in the
JSR and heat release (no flame occurred in the JSR).
Several gas chromatographs (GC), equipped with capillary
columns (Poraplot U, Molecular Sieve 5A, DB5ms, DB-624,
initiation reactions for the oxidation of toluene include C–C
and C–H bond cleavage,
Toluene Ð C6H5 þ CH3
Toluene Ð C6H5CH2 þ H
and a reaction with molecular oxygen (732).
ð730Þ
ð731Þ
2 3
Plot Al O /KCl, Carboplot P7), a thermal conductivity detec-
tor (TCD) and flame ionization detector (FID), were used for
stable species measurements. Compound identifications were
made via GC/MS analyses of the samples. An ion trap detec-
tor operating in electron impact ionization mode (GC/MS
7
The kinetics of reaction (730) was taken from Emdee. The
rate constant of reaction (731) consistent with the recommen-
Varian Saturn) was used. CH
FID after hydrogenation on a Pt/H
2
O and CO
2
were measured by
2
7
catalyst connected to
dation of Baulch et al. was taken from M u¨ ller-Markgraf and
2
2
9
the exit of the GC column. A good repeatability of the
measurements and a good carbon balance (ꢄ10%) were
obtained in the present experiments. The uncertainties of the
present results obtained by GC analyses were in the range
Troe. Reaction (730) was not measured directly ; only esti-
mates were derived either from experimental measurements
where reaction (731) dominates, or from kinetic modeling.
7
2
8
Brouwer et al. studied the kinetics of the decomposition of
toluene in a shock-tube at 1450–1900 K. They measured
k(731) in excellent agreement with most of the recent kinetic
5
–10%.
2
9–32
27
studies
ratio k(730)/k(731) was estimated by Brouwer et al. and by
and in agreement with data evaluations. The
2
8
Modeling
3
0
Braun-Unkhoff et al. who studied the decomposition of
toluene at high temperature (1380–1700 K) and moderate pres-
sure (1.5–6 atm). Both concluded that reaction (731) domi-
The kinetic modeling of the JSR experiments was performed
1
5
using the PSR computer code that calculates species concen-
trations from the balance between the net rate of production of
each species by chemical reaction and the difference between
the input and output flow rates of species. These rates are
computed from the kinetic reaction mechanism and the rate
constants of the elementary reactions calculated at the experi-
mental temperature, using the modified Arrhenius equation:
28
30
nates with k(730)/k(731) in the range 0.1–0.3 and p0.2.
These results are in excellent agreement with the values of
k(730) and k(731) used here since k(730)/k(731) ¼ 0.07 at
1
400 K and 0.27 at 1800 K. Consequently, the rate constants
used here for reactions (730) and (731) are fully consistent with
literature data (see Table 2). However, more information
regarding the pressure and temperature dependences of these
reactions would be helpful.
b
k ¼ AT expðꢁE=RTÞ:
The ignition delays were modeled using the Senkin computer
Propagation reactions proceed via H-atom abstraction by
atoms and radicals yielding benzyl. The kinetics of reactions
(732) and (733) were recently measured by Eng et al. We used
1
6
program. The ignition delays were computed assuming con-
stant volume under reflected shock-wave conditions.
The toluene–air burning velocities at 298 K, Su, were com-
3
3
their kinetic results here. The rate constant for reaction (734)
was derived from a fit to the available measurements. The
1
7
33
puted using the Premix computer package. Care was taken
in the calculations to reach the final solution (no evolution
of Su when the number of mesh points is increased).
3
kinetics of reaction (735) is from Hoffman et al.; that of reac-
4
3
tion (736) is from Hippler et al. The kinetics of reactions
5
The kinetic scheme used in the present study is based on the
comprehensive mechanism developed for the reduction of NO,
(738) and (739) were obtained from a fit to the NIST data
review. For reaction (740), we used the rate expression pro-
3
6
1
8
7
posed previously. The addition of H-atom to toluene yields
in simulated reburning conditions, by natural gas blends,
methane, ethane, ethylene, acetylene, propane, propene, n-
butane and isobutane and the oxidation of buta-1,3-diene.
benzene and methyl; the kinetics was measured by Robaugh
37
and Tsang.
1
9
20
The same kinetic scheme has been used to successfully simulate
the oxidation of benzene in a JSR at 1–10 atm and in a micro-
reactor at 0.46 atm, the ignition of benzene–oxygen–argon
mixtures under reflected shock wave conditions, flame speeds
of benzene–air mixtures and low-pressure benzene flame struc-
Benzyl radicals decompose thermally and react with mole-
cular oxygen, O (751, 752), OH (750) and HO (742). Reac-
2
tion (748) yields benzoxy that thermally decomposes
producing benzaldehyde (749). The kinetics of reactions
3
8
(745) and (746) were taken from Colket and Seery whereas
for the other reactions, we used previously proposed rate con-
stants. Benzyl alcohol is formed by OH addition to benzyl.
2
1
tures. Also, the oxidation of n-propylbenzene was success-
2
2
7
fully modeled using the same kinetic scheme. The reaction
mechanism used here consisted of 120 species and 920 reversi-
ble reactions. This mechanism, including references and ther-
mochemical data, is available from the authors. The rate
constants for the reverse reactions were computed from the
forward rate constants and the appropriate equilibrium con-
The reaction with atomic oxygen yields phenyl and formalde-
hyde. The oxidation of benzyl alcohol yields benzaldehyde.
The addition of H-atoms to benzyl alcohol yields benzene.
6 5
Benzaldehyde forms C H CO by thermal decomposition
and reactions with atoms and radicals that proceed by H-
atom abstraction. The reactions of benzaldehyde with OH
and H yield HCO. Benzoyl decomposes and reacts with oxy-
stants, K
data.
c
¼ kforward/kreverse , calculated using thermochemical
2
1–23
The pressure dependences of unimolecular reactions
and of some pressure-dependent bimolecular reactions were
taken into account when information was available (i.e.,
k(P,T)). First-order local sensitivity analyses, Si,j ¼ @ ln(mole
gen and HO
yield phenoxy. Although the reaction with O
H and C as a minor route, only reaction (709) was
included in this reaction scheme, since C was not
2
. Phenyl reactions with oxygen, OH and HO
2
2
might yield
6
4 2
H O
fraction of i)/@ ln(k ), were performed as well as reaction rates
6 4 2
H O
j
analyses by computation of rates of consumption (ROC) and
rates of production (ROP) for every species.
detected in these experiments. More direct kinetic investiga-
tions of these reactions are needed. Phenyl reactions with
The proposed kinetic scheme has a strong hierarchical
structure. Since most of the present mechanism has been pre-
sented in detail in previous papers, only the reaction sub-
mechanism for the oxidation of toluene is presented here
2
C H, ethylene, acetylene and diacetylene yield larger aro-
matics. Phenoxy radicals decompose, yielding two important
intermediates: cyclopentadienyl and phenol. The further reac-
tions of these species, yielding other important intermediates,
will be discussed in the next section.
(
Table 1). This sub-mechanism represents an updated version
Phys. Chem. Chem. Phys., 2002, 4, 1846–1854
1847

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ꢁ
1
3
Table 1 Reaction sub-set used in the present study. The Arrhenius parameters are given in units of s , cm , mol , cal
ꢁ1
a
b
Reaction
A
b
E
Ref.
Reactions pertaining to this toluene sub-mechanism
1
1
1
1
8
3
3
4
4
1
675
676
677
678
C
C
C
C
5
5
5
5
H
H
H
H
5
5
5
5
+ HO
2
Ð C
5
H
5
O13 + OH
3.00 ꢅ 10
9.00 ꢅ 10
4.00 ꢅ 10
1.00 ꢅ 10
0.44 ꢅ 10
0.0
0.0
0.0
0.0
0
0
7
+ OH Ð C
5
H
H
4
OH + H
+ CO
a
+ OH Ð C
4
6
4500
0
14
9
+ H(+M) Ð CPD(+M)
Low pressure limit:
Troe centering, F
ꢁ18.28
12 994
9
c
: a ¼ 0.068; T *** ¼ 400; T * ¼ 4136; T ** ¼ 5500
+ CO
O + H
+ CO
+ CO
O + H
O ! CO + C
Ð C
CPD + HO
Ð C
9,40
b
6
1
1
1
1
1
1
1
9
8
1
1
1
1
1
8
8
1
1
1
1
1
9
1
3
4
1
3
2
3
2
6
6
6
6
6
6
6
6
6
6
6
7
7
7
7
7
7
7
7
7
7
7
79
80
81
82
83
84
85
86
87
88
89
08
09
10
11
12
13
14
15
16
17
18
C
C
C
C
C
C
5
5
5
5
5
5
H
H
H
H
H
H
4
5
5
5
4
4
O + H Ð nC
+ O Ð C
+ O Ð nC
O13 Ð nC
OH Ð C
4
H
5
2.10 ꢅ 10
5.81 ꢅ 10
2.00 ꢅ 10
2.51 ꢅ 10
2.10 ꢅ 10
1.00 ꢅ 10
2.00 ꢅ 10
2.00 ꢅ 10
3.43 ꢅ 10
2.19 ꢅ 10
2.00 ꢅ 10
2.00 ꢅ 10
2.09 ꢅ 10
5.00 ꢅ 10
5.00 ꢅ 10
3.00 ꢅ 10
1.43 ꢅ 10
1.00 ꢅ 10
2.00 ꢅ 10
1.00 ꢅ 10
8.00 ꢅ 10
2.50 ꢅ 10
0.10 ꢅ 10
ꢁ13.3
0.0
0.0
40 810
20
5
H
4
c
4
H
5
0
a
4
H
5
0.0
0.0
43 900
48 000
53 000
25 000
11 660
ꢁ447
3000
10 000
15 000
7470
1000
0
7
5
H
4
7
4
H
4
0.0
0.0
14
7
CPD + O
2
5
H
5
+ HO
+ H
+ H
+ H
+ C
2
2
5
H
5
2
O
2
0.0
7
CPD + OH Ð C
5
H
5
2
O
1.2
1.8
7
CPD + H Ð C
CPD + H Ð C
5
H
H
5
3
2
7
4
2
2
3
3
3
2
H
4
0.0
d
C
C
C
C
C
C
C
C
C
C
C
6
6
6
6
6
6
6
6
6
6
6
H
H
H
H
H
H
H
H
H
H
H
6
5
5
5
5
5
5
5
5
5
5
+ iC
+ O
+ HO
4
H
5
Ð C
6
H
5
+ C
4
H
6
0.0
0.0
h
2
Ð C
6
H
5
O + O
7
2
Ð C
6
H
5
O + OH
O + H
0.0
0.0
e
+ OH Ð C
6
H
5
f
+ C
+ C
+ C
+ C
+ C
2
2
2
4
4
H Ð C
6
H
5
C
2
H
0.0
1.2
1391
3540
7647
0
g
H
H
H
H
4
2
2
4
Ð Styrene + H
36
h
3
3
3
3
4
5
Ð C
Ð C
Ð C
6
6
6
H
5
H
5
H
5
C
C
C
2
2
2
H + H
0.0
0.0
H + C
H + C
2
H
H
i
2
3
0.0
0.0
7647
55 400
0
h
O Ð C
5
H
5
+ CO
j
O + H + M Ð C
6
H
5
OH + M
0.0
ꢁ21.84
9
Low pressure limit:
Troe centering, F
13 880
9
c
: a ¼ 0.043; T *** ¼ 304; T * ¼ 60 000; T ** ¼ 5900
9,40
7
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
9
1
1
1
1
6
5
4
4
3
1
4
3
0
1
2
2
2
1
1
4
3
2
2
4
3
3
3
2
1
4
2
3
1
2
5
3
2
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
Toluene Ð C
Toluene Ð C
6
6
H
H
5
+ CH
3
1.40 ꢅ 10
3.00 ꢅ 10
3.00 ꢅ 10
3.00 ꢅ 10
1.00 ꢅ 10
6.30 ꢅ 10
1.26 ꢅ 10
2.40 ꢅ 10
8.88 ꢅ 10
1.01 ꢅ 10
2.10 ꢅ 10
4.00 ꢅ 10
4.00 ꢅ 10
2.00 ꢅ 10
6.32 ꢅ 10
2.00 ꢅ 10
6.03 ꢅ 10
6.31 ꢅ 10
3.16 ꢅ 10
1.30 ꢅ 10
2.00 ꢅ 10
1.58 ꢅ 10
1.00 ꢅ 10
1.00 ꢅ 10
1.05 ꢅ 10
2.00 ꢅ 10
8.43 ꢅ 10
1.20 ꢅ 10
2.11 ꢅ 10
1.40 ꢅ 10
3.98 ꢅ 10
1.02 ꢅ 10
2.00 ꢅ 10
1.71 ꢅ 10
1.20 ꢅ 10
9.04 ꢅ 10
5.00 ꢅ 10
1.20 ꢅ 10
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
1.2
0.0
0.0
0.0
0.0
99 800
88 194
43 062
22 010
2180
0
5
CH
2
+ H
CH
CH
CH
CH + OH
+ H
+ CH
CH
29
30
30
36
36
36
37
36
36
7
Toluene + O
Toluene + HO
2
Ð C
6
H
5
2
+ HO
+ H
+ H
2
2
Ð C
6
H
5
2
2 2
O
Toluene + OH Ð C
6
H
5
2
2
O
Toluene + O Ð C
6
H
5
2
Toluene + H Ð C
6
6
H
5
H
6
CH
2
2
8364
5123
8754
9514
4400
7500
7500
3700
3700
83 600
70 000
43 000
0
Toluene + H Ð C
3
Toluene + CH
3
Ð C
6
H
5
2 4
+ CH
Toluene + C
Toluene + C
2
6
H
H
5
Ð C
6
6
H
H
5
CH
CH
2
+ C
+ C
2
H
H
6
5
Ð C
5
2
6
6
Toluene + nC
Toluene + C
4
H
5
Ð C
6
H
5
CH
2
+ C
4
H
6
14
14
36
36
38
38
5
2
H
3
Ð C
6
H
5
CH
2
+ C
2
H
4
nC
nC
4
H
H
5
+ aC
+ pC
3
H
4
Ð Toluene + H
Ð Toluene + H
4
5
3 4
H
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
6
H
6
H
6
H
6
H
6
H
6
H
6
H
6
H
6
H
6
H
6
H
6
H
6
H
6
H
6
H
6
H
6
H
6
H
6
H
6
H
6
H
6
H
6
H
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
CH
CH
CH
CH
CH
CH
CH
CH
CH
CH
CH
CH
CH
CH
CH
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
Ð C
4
H
H
4
+ C
+ C
3
H
H
3
Ð C
5
5
2
2
+ O
2
Ð C
6
H
5
HCO + OH
CH O + OH
+ HO
O Ð C
2
Ð C
6
H
5
2
5
6
H
5
HCO + H
1100
0
5
+ OH Ð C
6
H
5
CH
HCO + H
+ CH
2
OH
30
5
+ O Ð C
+ O Ð C
6
H
H
5
5
0
6
2
O
0
o
+ C
3
H
3
Ð Toluene + C
OH Ð Toluene + C
! C HCO + HO
OH + OH ! C HCO + H
+ CH OH
! C HCO + Toluene + H
HCO + C + H
3
H
2
0
o
+ C
6
H
5
6
H
5
O
9500
41 400
2583
5148
9500
4400
83 701
39 000
11 665
ꢁ447
5123
3080
4928
5148
7
OH + O
2
6
H
5
2
+ H
7
6
H
5
2
O + H
7
OH + H Ð C
6
H
6
2
7
OH + C
OH + C
6
6
5
H
H
5
CH
! C
2
6
H
5
7
5
6
H
5
6
H
6
7
HCO Ð C
HCO + O
HCO + HO
6
H
CO + H
CO + HO
36
k
2
Ð C
6
H
5
2
2
Ð C
6
H
5
CO + H
2
O
2
k
HCO + OH Ð C
HCO + OH Ð C
6
6
H
H
5
CO + H
2
O
OH + HCO
7
3
2
3
3
5
14
7
HCO + O Ð C
6
H
5
CO + OH
HCO + H Ð C
HCO + H Ð C
6
H
H
5
CO + H
+ HCO
2
7
6
6
7
1
848
Phys. Chem. Chem. Phys., 2002, 4, 1846–1854

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Table 1 (continued)
a
b
Reaction
A
b
E
Ref.
3
1
1
1
1
7
7
7
7
7
68
69
70
71
72
C
C
C
C
C
6
6
6
6
6
H
H
H
H
H
5
5
5
5
5
HCO + CH
HCO + C
CO Ð C
CO + O
CO + HO
3
Ð C
Ð C
+ CO
Ð C O + CO
! C + CO
6
H
5
CO + CH
4
2.77 ꢅ 10
7.01 ꢅ 10
3.98 ꢅ 10
3.00 ꢅ 10
2.00 ꢅ 10
2.8
0.0
0.0
0.0
0.0
5773
4400
7
1
4
0
3
6
H
5
6
H
5
CO + C
6
H
6
7
6
H
5
29 401
2870
0
7
2
6
H
5
2
14
14
2
6
H
5
2
+ OH
Other important reactions
H + O
HCO + M ¼ H + CO + M
HCO + O
1
1
9
1
1
9
8
1
8
4
4
9
1
1
1
1
7
1
1
1
1
2
4
6
2
3
4
9
1
1
1
1
1
1
2
2
5
5
5
6
6
6
6
8
9
2
¼ OH + O
1.85 ꢅ 10
1.85 ꢅ 10
2.11 ꢅ 10
4.38 ꢅ 10
4.88 ꢅ 10
1.72 ꢅ 10
1.26 ꢅ 10
4.09 ꢅ 10
2.00 ꢅ 10
1.98 ꢅ 10
4.62 ꢅ 10
1.40 ꢅ 10
2.17 ꢅ 10
1.00 ꢅ 10
3.00 ꢅ 10
5.00 ꢅ 10
2.00 ꢅ 10
3.00 ꢅ 10
1.66 ꢅ 10
1.00 ꢅ 10
4.53 ꢅ 10
1.85 ꢅ 10
0.0
ꢁ1.0
1.1
16 812
17 000
ꢁ620
14 656
22 773
ꢁ447
2170
8843
30 100
656
l
7
5
m
36
36
n
o
p
27
q
r
0
2
¼ CO + HO
2
1
5
8
CH
CH
CH
CH
CH
3
3
2
2
2
+ O
2
¼ CH O + OH
O + M ¼ CH O + H + M
O + OH ¼ HCO + H
O + H ¼ HCO + H
O + CH
2
0.0
0.0
8
2
12
14
16
60
67
68
29
45
65
87
89
34
36
40
44
98
01
2
O
1.2
1.6
2
2
3
¼ HCO + CH
¼ HCCO + OH
+ O ¼ CH + CO
+ O ¼ HCCO + H
¼ CO + CO + H
¼ CH O + HO
+ C
+ O ! OC
! C + CH
+ OH ¼ iC + H
+ O ¼ aC + CO
+ CH + CH
¼ iC
+ O CO + HCCO
¼ CH
+ H ¼ C
+ O
¼ CH
4
0.0
1.5
C
C
C
2
2
2
H
2
H
2
H
2
+ O
2
2
2.6
2.6
656
0
r
HCCO + O
CH OH + O
2
2
1.0
0.0
q
s
4
4
3
4
2
2
2
2
4690
75 000
80
C
C
4
4
H
H
6
¼ C
2
H
4
2
H
2
0.0
0.0
36
t
6
4
H
6
OC
4
H
6
2
H
4
2
CO
1.0
2.0
78 000
2000
1810
9499
0
k
q
u
v
C
C
C
4
4
4
H
4
H
4
H
4
4
H
3
2
O
3
3
H
4
0.0
3
4
H
3
4
3.7
2
4
3
iC
4
H
3
2
2
0.0
q
l
C
C
2
H
H
2
2
H
3
ꢁ0.7
ꢁ3.3
2688
3892
2
3
2
2
O + HCO
w
a
Nomenclature: C
penta-1,3-diene; C
5
H
5
, cyclopentadienyl; C
O, cyclopentadienone; nC
H, phenylacetylene; C
CH OH; benzyl alcohol; C
5
H
5
O: 1,3-cyclopentadienonyl; C
, buta-1,3-dienyl; C , vinylacetylene; C
CH , benzyl; aC , allene; pC , propyne; C
CO, phenylformyl; C OH, phenol. Ref.: (a) Based on ref. 7; (b) M. U. Alzueta,
5
H
4
OH, hydroxycyclopentadienyl; C
, benzene; iC
, propargyl; C
4
H
6
, buta-1,3-diene; CPD; cyclo-
, buta-2,3-dienyl; C , phenyl;
HCO, benzaldehyde;
5
H
4
4
H
5
4
H
4
6
H
6
4
H
5
6 5
H
C
C
6
H
H
5
O, phenoxy; C
6
H
5
C
2
6
H
5
2
3
H
4
3
H
4
3
H
3
6 5
H
b
6
5
CH O, benzoxy; C
2
6
H
5
2
6
H
5
6 5
H
P. Glarborg and K. Dam-Johansen, Int. J. Chem. Kinet., 2000, 32, 498; (c) X. Zhong and J. W. Bozzelli, J. Phys. Chem. A, 1998, 102, 3537;
(
d) Based on ref. 32; (e) D. A. Bittker, Combust. Sci. Technol., 1991, 79, 49; (f) J. A. Miller and C. F. Melius, Combust. Flame, 1992, 91, 21;
g) Y. Tan and P. Frank, P., Proc. Combust. Inst., 1996, 26, 1105; (h) E. Heckmann, H. Hippler and J. Troe, Proc. Combut. Inst., 1996, 26,
(
543; (i) M. Frenklach, D. W. Clary, W. C. Gardiner, Jr. and S. E. Stein, Proc. Combust. Inst., 1984, 20, 887; (j) S. Olivella, A. Sole and A. Gar-
cia-Raso, J. Phys. Chem., 1995, 99, 10 549; (k) This work; (l) D. L. Baulch, L. J. Cobos, R. A. Cox, C. Esser, C. P. Frank, Th. Just, J. A. Kerr, M. J.
Pilling, J. Troe, R. W. Walker and J. Warnatz, J. Phys. Chem. Ref. Data, 1992, 21, 411; (m) R. S. Timonen, E. Ratajczak, D. Gutman and A. F.
Wagner, J. Phys. Chem., 1987, 91, 5325; (n) P. J. Wantuck, R. C. Oldenborg, S. L. Baughcum and K. R. Winn, Proc. Combust. Inst., 1989, 22, 973;
(
o) W. Tsang and R. F. Hampson, J. Phys. Chem. Data, 1986, 15, 1087; (p) T. K. Choudhury and M. C. Lin, Combust. Sci. Technol., 1989, 64, 19;
q) J. A. Miller and C. F. Melius, Combust. Flame, 1992, 91, 21; (r) K. Mahmud and A. Fontijn, J. Phys. Chem., 1987, 91, 1918; (s) H. Grotheer, G.
(
Riekert, D. Walter and Th. Just, J. Phys. Chem., 1988, 92, 4028; (t) R. J. Cvetanovic, J. Phys. Chem. Ref. Data, 1987, 16, 261; (u) R. P. Lindstedt
and G. Skevis, Proc. Combust. Inst., 1996, 26, 703; (v) P. Dagaut and M. Cathonnet, Combust Sci. Technol., 1998, 140, 225; (w) J. W. Bozzelli and
A. M. Dean, J. Phys. Chem., 1993, 97, 4427.
Results and discussion
4 6
pyne), 1,3-C H , vinylacetylene, cyclopentadiene, benzalde-
hyde, benzene, dibenzyl, styrene, and toluene by probe
sampling and GC analysis. The products detected are in agree-
ment with the experimental results obtained in previous PFR
The oxidation of toluene in a JSR at 1 atm
The oxidation of toluene was studied at equivalence ratios of
0.5, 1 and 1.5, at residence times, t, of respectively 0.07, 0.1
and 0.12 s. From these experiments, molecular species concen-
4
,6
studies. The present data were used to propose a detailed
chemical kinetic reaction mechanism for the oxidation of
toluene. Figs. 1 to 3 present the results obtained at 1 atm for
j ¼ 0.5, 1 and 1.5, respectively.
tration profiles were obtained for O , H , CO, CO , CH O,
2
2
2
2
CH
4
, C
H
2 2
, C
H
2 4
, C
2
H
6
, aC
3
H
4
(allene) and pC
3
H
4
(pro-
ꢁ
1
3
Table 2 Comparison of available kinetic data for toluene decomposition (731). The Arrhenius parameters are given in units of s , cm , mol , cal
ꢁ1
A
E
Temperature/K
k(730)/k(731)
Ref.
15
15
15
15
16
15
15
3
2
2
3
1
6
3
.10 ꢅ 10
89 205
88 887
88 194
89 427
91 779
90 344
88 194
920–2200
1450–1900
1500–1900
1380–1700
300–1200
1100–1900
1000–2000
—
0.1 to 0.3
0.1
27
28
.82 ꢅ 10
.00 ꢅ 10
.60 ꢅ 10
.82 ꢅ 10
.31 ꢅ 10
.00 ꢅ 10
29
30
p0.2
—
—
31
32
0.07 to 0.3
This work
Phys. Chem. Chem. Phys., 2002, 4, 1846–1854
1849

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Fig. 1 Toluene oxidation in a JSR at 1 atm. The initial conditions were: toluene, 0.15%; O
mental data (symbols) are compared to computations (lines and small symbols).
2
, 2.70%, N
2
, 97.15%; t ¼ 0.07 s; j ¼ 0.5. Experi-
The experimental results show that besides CO, H
CO , the major intermediate products are acetylene, benzene,
methane, ethylene, formaldehyde, vinylacetylene, and benzal-
dehyde. The minor products are propyne, cyclopentadiene,
allene, buta-1,3-diene, ethane, styrene, and dibenzyl. As can
be seen from these figures, overall the proposed model fairly
2
and
well represents the experimental data. However, it should be
noticed that the model over-predicts the formation of acety-
lene, dibenzyl and benzaldehyde at low fuel conversion.
The kinetic scheme proposed recently was also tested
against the present data. As can be seen from Fig. 4, the present
experimental data are poorly represented by the model: The
2
9
Fig. 2 Toluene oxidation in a JSR at 1 atm. The initial conditions were: toluene, 0.15%; O
data (symbols) are compared to computations (lines and small symbols).
2
, 1.35%, N
2
, 98.5%; t ¼ 0.10 s; j ¼ 1.0. Experimental
1
850
Phys. Chem. Chem. Phys., 2002, 4, 1846–1854

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Fig. 3 Toluene oxidation in a JSR at 1 atm. The initial conditions were: toluene, 0.15%; O
mental data (symbols) are compared to computations (lines and small symbols).
2
, 0.675%, N
2
, 99.175%; t ¼ 0.12 s; j ¼ 1.5. Experi-
predicted reactivity is much higher than in the experiments, the
maximum mole fractions of acetylene, ethylbenzene, benzalde-
hyde and styrene are over-predicted whereas those of formalde-
hyde, methane, benzene, ethylene and vinylacetylene are under-
predicted. No ethane, propyne and allene are predicted since
Sensitivity analyses and reaction path analyses, through spe-
cies reaction rate of production (ROP) and rate of consump-
tion (ROC) computations, have been used to elaborate the
proposed mechanism and interpret the results. These computa-
tions show that the kinetics of toluene oxidation, in the present
experimental conditions, is mainly sensitive to a limited num-
9
these species were not considered in the scheme.
Fig. 4 Toluene oxidation in a JSR at 1 atm. The initial conditions were: toluene, 0.15%; O
data (symbols) are compared to computations (lines and small symbols) using the kinetics scheme and the thermochemical data of Davis et al.
2
, 1.35%, N
2
, 98.5%; t ¼ 0.10 s; j ¼ 1.0. Experimental
9
Phys. Chem. Chem. Phys., 2002, 4, 1846–1854
1851

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ber of reactions pertaining to the toluene oxidation sub-
mechanism and to reactions of simple intermediates. At
ꢁ0.22) and CH
3
(ROC(640) ¼ ꢁ0.09). iC
4
H
3
mostly reacts
with molecular oxygen (644), yielding ketene and ketenyl.
Acetylene is mostly formed by decomposition of benzyl
(ROP(746) ¼ 0.26), butadienyl (ROP(613) ¼ 0.34), and vinyl,
1
300 K, in stoichiometric conditions (conditions of Fig. 2),
toluene computed mole fractions are mostly sensitive to reac-
tion (6), S ¼ ꢁ0.4, to reactions of toluene with
S(731) ¼ 0.45, S(736) ¼ 0.16, S(737) ¼ ꢁ0.46) and to ther-
H
ROP(898) ¼ 0.3. The oxidation of acetylene by O and O
2
(
mainly yields HCCO: ROC(167) ¼ ꢁ0.12; ROC(168) ¼
ꢁ0.28; ROC(160) ¼ ꢁ0.52. Ethylene is mainly produced from
the decomposition of ethyl, ROP(894) ¼ 0.43, and also from
the buta-1,3-diene oxidation submechanism: ROP(565) ¼ 0.11
0.11 and ROP(589) ¼ 0.16. Ethylene is mostly consumed by
mal decomposition, S(746) ¼ ꢁ0.33.
According to this modeling, the oxidation of toluene pro-
ceeds according to the scheme depicted in Fig. 5. The size of
the arrows indicates the importance of the reaction In stoichio-
metric conditions and low fuel conversion (1080 K), toluene
3
reaction with O, OH, and CH . Butadiene is almost exclu-
mostly reacts with OH (ROC(734) ¼ ꢁ0.43), O
732) ¼ ꢁ0.29) and HO (ROC(733) ¼ ꢁ0.10) whereas reac-
tions with H and O atoms are of minor importance.
2
(ROC
sively formed in reaction (677). It mostly decomposes via
(565), ROC(565) ¼ ꢁ0.21, and oxidizes, ROC(587) ¼ ꢁ0.25.
(
2
2
Methane is formed by reaction of methyl radicals with H ,
At higher fuel conversion (1300 K), toluene reacts with H
ROC(734) ¼ ꢁ0.24; ROC(736) ¼ ꢁ0.40) and OH (ROC
737) ¼ ꢁ0.28). Benzyl, predominantly formed by reaction
736), mostly recombines with H-atoms to yield toluene,
CH O and C H . It is mostly consumed by reaction with
2 4 4
(
(
(
OH (71%) and O (29%). Methyl is mostly produced by H-atom
displacement reaction of H with toluene (67%) and mostly
recombines (25%), yielding ethane. A smaller fraction reacts
with H2 (16%), yielding methane, and O2 , yielding
ROC(ꢁ731) ¼ ꢁ0.59, and decomposes: ROC(746) ¼ ꢁ0.22.
Its reaction with HO yields benzoxy and OH
2
CH
formed by recombination of methyl, predominantly reacts
with OH (44%), H (31%), O (15%), and CH (9%). Allene is
2 3
O + OH and CH O + O (15%). Ethane, almost exclusively
(
ROC(748) ¼ ꢁ0.05). Benzoxy, formed in reaction (748),
decomposes into benzaldehyde and H (749). Benzaldehyde
predominantly reacts by thermal decomposition (ROC
3
mostly produced by the oxidation of vinylacetylene by O-
atoms (636). It mostly isomerizes (47%), yielding propyne, that
in turn is mostly oxidized by reactions with O and OH, yield-
(
760) ¼ ꢁ0.37) and H-atom abstraction (ROC(763) ¼ ꢁ0.20;
ROC(766) ¼ ꢁ0.23). C H CO thermally decomposes, yielding
6 5
phenyl and CO (770). Benzene, mostly formed in (737), mainly
reacts with O (ROC(703) ¼ ꢁ0.64) and OH (ROC(701) ¼
2 3 3
ing HCCO, CH CO, and C H .
Higher compounds are formed: ethylbenzene, styrene and
dibenzyl. Ethylbenzene is produced by recombination of
methyl and benzyl. Dibenzyl is produced by recombination
of benzyl radicals. Styrene is almost entirely formed by decom-
position of 1-phenylethyl, derived from ethylbenzene degrada-
tion. Formaldehyde formation is due to the oxidation of
methyl (48), vinyl (901) and hydroxymethyl (245). It mostly
reacts with H (114, 36%), OH (112, 38%) and CH (116,
3
13%) by H-atom abstraction. Formyl decomposes (25, 70%)
and reacts with molecular oxygen (30, 30%), yielding CO, H
ꢁ
2
0.26). Phenyl predominantly reacts with O , yielding phe-
noxy, ROC(709) ¼ ꢁ0.79. Phenoxy, mostly formed by reac-
tions (703) and (709), ROP(703) ¼ 0.51 and ROP(709) ¼
0
.45, decomposes via (717) yielding cyclopentadienyl and
CO. More kinetic information is still needed for this reaction.
At this stage, the original aromatic ring has disappeared.
Cyclopentadienyl, is mostly formed by reactions (717),
ROP(C H ) ¼ 0.587, and (746), ROP(C H ) ¼ 0.3. It reacts
5
5
5
5
with O (ROC(681) ¼ ꢁ0.20; ROC(680) ¼ ꢁ0.05), H (ROC
(
678) ¼ ꢁ0.13), HO
2
(ROC(675) ¼ ꢁ0.19) and OH
2
and HO . The fuel is mostly consumed by H and OH. Atomic
hydrogen is mostly formed by reactions (25) and (229) whereas
OH radicals are mostly formed by reaction (6).
(
ROC(676) ¼ ꢁ0.17; ROC(677) ¼ ꢁ0.14).
C
H
5 4
O
mostly
decomposes via (683) yielding vinylacetylene and CO.
OH, formed in reaction (676), decomposes thermally
via (683) yielding C O. Cyclo-1,3-pentadiene mostly reacts
with O
5 4
C H
5 4
H
The ignition of toluene–oxygen–argon mixtures
2
(ROC(685) ¼ ꢁ0.19), H (ROC(688) ¼ ꢁ0.39) and
OH (ROC(687) ¼ ꢁ0.24). At this stage, cyclic species have
The ignition delays of toluene–oxygen–argon mixtures has
been measured by Burcat et al. over a wide range of experi-
3
been converted into linear products. Vinylacetylene, mostly
formed by decomposition of C
H
5 4
O (684), predominantly
mental conditions (0.5 to 1.5% mol of fuel, 4.48–13.45% mol
of oxygen, equivalence ratio ranging from 0.33 to 1 and tem-
reacts with OH (ROC(634) ¼ ꢁ0.43), O (ROC(636) ¼ ꢁ0.22)
perature, T
wave conditions. The pressure behind the reflected shock wave,
, was in the range 1.95–8.85 atm). As can be seen from
5
, in the range 1339–1797 K) in reflected shock
P
5
Fig. 6a, the model tends to predict longer ignition delays than
measured although the computed overall activation energy fits
the experiments well. Fig. 6b presents a comparison of the
kinetic modeling and the ignition delay measured by Pengloan
3
3
et al. Very good agreement between the data and the model-
ing was obtained. Sensitivity analyses (Fig. 7) indicate that the
ignition delays are mostly sensitive to the kinetics of a limited
number of reactions. Increasing the rate of reactions (6), (676),
(
709), (732), (746), (748), and (751) reduces the computed igni-
tion delays by production of radicals. Conversely, increasing
the rate of reactions (ꢁ731), (734), and (736), that act as
chain-terminating steps or consume H and OH (active radi-
cals) to produce less reactive species such as benzyl which is
resonantly stabilized, increases the computed ignition delays.
The toluene–air burning velocities
The proposed kinetic scheme was also tested at higher tem-
perature by modeling laminar burning velocities of atmo-
spheric toluene–air flames at 298 K. The data of Davis et
Fig. 5 Reaction paths for the oxidation of toluene in a JSR at 1 atm
j ¼ 1, 0.15% of toluene, t ¼ 0.10 s, 1300 K).
9
(
al. obtained for benzene–air and toluene–air flames were used
1
852 Phys. Chem. Chem. Phys., 2002, 4, 1846–1854

View Article Online
Fig. 8 Benzene–air and toluene–air burning velocities at 298 K and
atmospheric pressure. Comparison between the experimental data of
9,10
Davis et al.
(large symbols) and this modeling (line).
ing to the CO-sub-mechanism, phenoxy and cyclopentadienyl
reactions.
Conclusion
The oxidation of toluene has been studied in a JSR over the
temperature range 1000–1375 K, for equivalence ratios ran-
ging from 0.5 to 1.5. Molecular species concentration profiles
were obtained by probe sampling and GC analysis. These
experiments were simulated using a detailed kinetic reaction
mechanism already validated for the oxidation of benzene over
a wide range of conditions (0.46–10 atm, 0.19 p j p 1.5, 950–
Fig. 6 Comparison between experimental (symbols) and computed
ignition delays of toluene–oxygen–argon mixtures. (a) The data were
3
taken from Burcat et al. The initial mole fractions were (A):
0
O
.01495 toluene, 0.1345 O
2
, 0.85055 Ar; (D): 0.00497 toluene, 0.0448
33
2
, 0.95023 Ar; P
5
¼ 2.5 atm. (b) The data of Pengloan et al. were
used. The initial mole fractions were j ¼ 0.5: 0.4% toluene and 7.2%
oxygen; j ¼ 1:0.4% toluene and 3.6% oxygen; j ¼ 1.5: 0.4% toluene
and 2.4% oxygen.
1
350 K). Overall, the proposed kinetic model represents well
the present set of data, in contradiction with previously pro-
7
,9
posed kinetic mechanisms. The kinetic modeling was used
to delineate the main reactions involved in the oxidation of
toluene, confirming the general reaction mechanism proposed
here. The authors measured the burning velocities using their
counter-flow flame technique, extrapolating the data to zero-
stretch conditions via linear and non-linear fits with an uncer-
7
earlier. Modeling of the ignition of toluene–oxygen–argon
mixtures and of the burning velocities of toluene–air mixtures
was also successfully performed using the proposed scheme.
ꢁ
1
tainty of ꢀ2 cm s . Fig. 8 compares the predictions of the
model with the experimental flame speeds over a wide range
of equivalence ratio. The symbols represent the data obtained
using a non-linear extrapolation to zero-stretch. One can
observe that the agreement between this model and experiment
is generally good for both benzene–air and toluene–air flame
speeds. Sensitivity analyses showed that burning velocities of
toluene–air flames are mostly sensitive to the kinetics of
References
1
2
J. M. Andino, J. N. Smith, R. C. Flagan, W. A. Goddard, III and
J. H. Seinfeld, J. Phys. Chem., 1996, 100, 10 967.
A. Burcat, R. C. Farmer, R. L. Espinoza and R. A. Matula, Com-
bust. Flame, 1979, 36, 313.
2
H + O OH + O, followed in importance by reactions pertain-
3
4
A. Burcat, C. Snyder and T. Brabbs, NASA TM-87312, 1986.
C. Venkat, K. Brezinsky and I. Glassman, Proc. Combust. Inst.,
1
982, 19, 143.
5
K. Brezinsky, T. A. Litzinger and I. Glassman, Int. J. Chem.
Kinet., 1984, 16, 1053.
6
7
K. Brezinsky, Prog. Energy Combust. Sci., 1986, 12, 1.
J. L. Emdee, K. Brezinsky and I. Glassman, J. Phys. Chem., 1992,
9
6, 2151.
R. R. Baldwin, M. Scott and R.W. Walker, Proc. Combust. Inst.,
986, 21, 991.
S. G. Davis, H. Wang, K. Brezinsky and C. K. Law, Proc. Com-
bust. Inst., 1996, 26, 1025.
S. G. Davis and C. K. Law, Combust. Sci. Technol., 1998, 140,
8
9
0
1
2
3
1
1
1
1
1
4
27.
S. D. Klotz, K. Brezinsky and I. Glassman, Proc. Combust. Inst.,
998, 27, 337.
R. P. Lindstedt and L. Q. Maurice, Combust. Sci. Technol., 1996,
20, 119.
1
1
P. Dagaut, M. Cathonnet, J.-P. Rouan, R. Foulatier, A. Quilgars,
J.-C. Boettner, F. Gaillard and H. James, J. Phys. E, 1986, 19,
2
07.
A. El Bakali, M. Braun-Unkhoff, P. Dagaut, P. Frank and M.
1
4
Fig. 7 Sensitivity spectrum for the ignition of a toluene–oxygen–
argon (mixture A). The sensitivity coefficients are relative to reaction
Cathonnet, Proc. Combust. Inst., 2000, 28, 1631.
15 P. Glarborg, R. J. Kee, J. F. Grcar and J. A. Miller, PSR: A FOR-
TRAN program for modeling well-stirred reactors, SANDIA
(6).
Phys. Chem. Chem. Phys., 2002, 4, 1846–1854
1853

View Article Online
27 D. L. Baulch, L. J. Cobos, R. A. Cox, P. Frank, G. Hayman, Th.
Just, J. A. Kerr, T. Murrells, M. J. Pilling, J. Troe, R. W. Walker
and J. Warnatz, J. Phys. Chem. Ref. Data, 1994, 23, 847.
28 L. D. Brouwer, W. M u¨ ller-Markgraf and J. Troe, J. Phys. Chem.,
1988, 92, 4905.
29 W. M u¨ ller-Markgraf and J. Troe, Proc. Combust. Inst., 1988, 21, 815.
30 M. Braun-Unkhoff, P. Frank and Th. Just, Proc. Combust. Inst.,
1989, 22, 1053.
31 U. Brand, H. Hippler, L. Lindemann and J. Troe, J. Phys. Chem.,
1990, 94, 6305.
National Laboratories Report, SAND86-8209, Livermore, CA,
986.
A. E. Lutz, R. J. Kee and J. A. Miller, Senkin: a Fortran program
for predicting homogeneous gas phase chemical kinetics with
sensitivity analysis, SANDIA National Laboratories Report,
SAND87-8248, Livermore, CA, 1990.
R. J. Kee, J. F. Grcar, M. D. Smooke and J. A. Miller, A FOR-
TRAN Program for Modeling Steady Laminar One-Dimensional
Premixed Flames, SANDIA National Laboratories Report,
SAND85-8220, Livermore, CA, 1985.
1
1
6
7
1
1
1
2
2
2
2
2
8
9
0
1
2
3
4
P. Dagaut, F. Lecomte, S. Chevailler and M. Cathonnet, Com-
bust. Sci. Technol., 1998, 139, 329.
P. Dagaut, J. Luche and M. Cathonnet, Proc. Combust. Inst.,
32 H. Hippler, C. Reihs and J. Troe, Z. Phys. Chem., Neue Folge,
1990, 167, 1.
33 R. A. Eng, C. Fittschen, A. Gebert, P. Hibomvschi, H. Hippler
and A.-N. Unterreiner, Proc. Combust. Inst., 1998, 27, 211.
34 A. Hoffmann, M. Klatt and H. Gg. Wagner, Z. Phys. Chem.,
Neue Folge, 1990, 168, 1.
35 H. Hippler, C. Reihs and J. Troe, Z. Phys. Chem., Neue Folge,
1990, 167, 1.
36 W. G. Mallard, F. Westley, J. T. Herron, R. F. Hampson and
D. Frizzell, NIST Chemical Kinetics Database, Version 2Q98,
1998.
37 D. Robaugh and W. J. Tsang, Phys. Chem., 1986, 90, 4159.
38 M. B. Colket III and D. Seery, Proc. Combust. Inst., 1994, 25, 883.
39 G. Pengloan, P. Dagaut, N. Djebaili-Chaumeix, C.E. Paillard and
M. Cathonnet, Colloque Combustion Propre, Orl e´ ans, 6–8 June
2001, p. 9.
2
000, 28, 2459.
P. Dagaut and M. Cathonnet, Combust. Sci. Technol., 1999, 140,
25.
2
A. Ristori, P. Dagaut, A. El Bakali, G. Pengloan and M. Cathon-
net, Combust. Sci. Technol., 2001, 167, 223.
P. Dagaut, A. Ristori, A. El Bakali and M. Cathonnet, Fuel, 2002,
81, 173.
Y. Tan, P. Dagaut, M. Cathonnet and J.-C. Boettner, Combust.
Sci. Technol., 1994, 102, 21.
R. J. Kee, F. M. Rupley and J. A. Miller, Thermodynamic data
base, SANDIA National Laboratories Report, SAND87–8215,
Livermore, CA, 1991.
C. Muller, V. Michel, G. Scacchi and G.-M. C oˆ me, J. Chim. Phys.
Phys.-Chim. Biol., 1995, 92, 1154.
P. Dagaut and M. Cathonnet, Combust. Sci. Technol., 1998, 137,
2
5
6
40 Troe’s broadening falloff factor (R. G. Gilbert, K. Luther and
¼ (1ꢁa)
2
J. Troe, Ber. Bunsen-Ges. Phys. Chem., 1983, 87, 169. F
exp(ꢁT/T ***) + a exp(ꢁT/T *) + exp(ꢁT **/T).
c
237.
1
854
Phys. Chem. Chem. Phys., 2002, 4, 1846–1854